Troubleshooting Suspension on 1996 Heritage Boat Trailer with 3500-lb GVWR

Question

Question:

Ive blown two new tires one on each side of a boat trailer Ive recently purchased. GVWR is 3500lbs. 17foot Celebrity Ski boat. Both times the lugs were shaved off each hub so had to replace those as well. The current springs on it are 6 leaf and measurement from center mounting holes on trailer are 27. Im just curious if it is time to replace the leaf springs but the ones on it dont appear to be standard for a 3500lb trailer so thinking they have been replaced at some point. Just looking for what is causing the tire blowing issue. Stock calls for 14inch wheels, trailer had 15inch both of these blew on so I went back to stock ones today. Thanks in advance.

asked by: Ryan I

0

Expert Reply:

Thank you for the photo of your boat trailer suspension.

If your boat trailer's identification plate indicates a gross vehicle weight rating (GVWR) of 3500-lbs for the loaded trailer then I think your springs could be too heavy, rated for too much weight. Your axle may have its own identification sticker or plate that will let you confirm its own weight rating. If the trailer has one axle and it is rated for 3500-lbs then I would suspect you are right that the previous owner installed springs rated for a heavier axle.

If this were the case it would explain why you have had both blown tires AND sheared-off lugs on your hubs. If the leaf springs are rated for much more weight than the trailer actually carries then they would provide little or no actual cushioning of road impacts; this would easily explain the damage to your tires and hubs.

You will want to confirm the axle capacity and then select leaf springs rated appropriately for that axle rating. If you contact the trailer maker with the trailer's VIN they should be able to tell you the weight rating of the original axle. Or it may appear on a sticker or plate on the axle beam.

The double-eye springs we offer for 3500-lb axles, shown on the linked page, are typically 3-leaf or 4-leaf like # e54SR. Different springs with the same weight rating can have varying numbers of leaves but it would be unusual for a 6-leaf spring to be rated for a 3500-lb axle. You might care to check out the linked article on trailer suspensions.

We can also help you with replacement tires for your trailer. I linked our main page for 14-inch trailer tires and you can click on your size to see all options in various weight load ranges.

expert reply by: Adam R

0

click to enlarge

Answer 1

In order to determine the torque rating for the lug nuts on your trailer you will need to know check out the chart I attached that shows all of the torque specs for all the trailer lugs available based on stud size, wheel material and wheel size.

view full answer...

Answer 2

Thank you for providing the specs for the suspension components that you already have. Correct hanger spacing really depends on the components being used such as springs, hangers and equalizers. Most of the hanger spacing dimensions that we have are…

view full answer...

Answer 3

For a single axle trailer, you want the shackle strap to be able to move so that you have the spring deflection needed for your suspension. Angled like the photo or even almost vertical is fine you just don't want the shackle strap to bind and…

view full answer...

Answer 4

To find the load capacity for your axle you should look on the trailer VIN plate or sticker that lists the VIN number. The weight rating of the axle should be listed on that same plate or sticker. Also, the axle could have a tag or plate on it that…

view full answer...

Answer 5

Well shackle length is mainly based on the height difference between the front and rear hangers. The rear hanger normally doesn't hang as low as the front so that the shackle can offset the difference and add the ability to move. What is the…

view full answer...

Answer 6

I have attached for you below some common torque values needed for a trailer suspension system but a lot of these will vary by bolt size and other factors. U-Bolts: Varies by Size - 1/2" bolts: 45 ft/lbs - 70 ft/lbs, 9/16" bolts: 65 ft/lbs…

view full answer...

Answer 7

I contacted MORryde and this does happen from time to time as the weight of the trailer can spread out the axles due to downward pressure on the springs/suspension. Odds are the 35" wheel base #MR27ZR will be the correct one for you, but they…

view full answer...

Answer 8

The absolute best cushioned equalizer that fits the dimensions you mentioned having would be the MORryde ALLTREK 4000 part #MR89DR as this is only option to provide vertical and horizontal cushioning. This would make a big difference and you'd be…

view full answer...

Answer 9

To correctly measure a leaf spring, you'll want to jack the trailer up on jack stands so the axle is hanging freely, then measure directly across from the center of one spring eye to the other, as shown in the provided diagram. The height of the…

view full answer...

Answer 10

Yes, axle spread and wheel base by definition are the same measurements. You will measure from the center of one axle to the center of the 2nd axle to determine what you axle spread is. This may be difficult as some wheels and covers will make this…

view full answer...

Answer 11

Hey Doug, thanks for reaching out! The MORryde ALLTREK 4000 #MR89DR dimensions can be a bit difficult to explain via text so I've attached an image giving you the dimensions you're asking about!

view full answer...

Answer 12

I understand your worry Tom, and I have a couple recommendations. First is the MORryde ALLTREK 4000 Shock Absorbing Equalizers #MR89DR which has a height of 4-1/2" for the mounting bolts. This is also 6-1/2" in width like the shorter…

view full answer...

Troubleshooting Suspension on 1996 Heritage Boat Trailer with 3500-lb GVWR

Product Page this Question was Asked From

Featured Help Information

Miscellaneous Media

Continue Researching